Drivers not wanted: The autonomous car technology of tomorrow

This article was taken from the February 2011 issue of Wired
magazine. Be the first to read Wired's articles in print before
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Crash avoidance and automatic parking are just the start.
Tomorrow's cars will be brains on wheels.

The 300km trip from San Francisco to Lake Tahoe can be a
frustrating slog in the wintertime traffic on Interstate 80. Speeds
in the fast lane swing from 120kph to 50kph for no discernible
reason. Slow, fast, faster, slow. Hit rush hour in Sacramento -- or
Donner Pass on a snowy day -- and you'll see the speedometer's
needle tapping the 15kph mark like a woodpecker on a tasty log.

Driver of manual cars collapse with dead legs on the side of the
road; even the automatic-enabled P-R-N-D crowd can be seen
massaging their sore knees at roadside burger joints and woodsy
rest stops.

Not me. I'm playing the licence-plate game and humming through
playlists with a few friends, happy and comfortable in a borrowed
Mercedes-Benz S550, a luxury car that's currently justifying
the pants off its $100,000 (£63,600) price tag. We're bopping
through the same unpredictable range of velocities as everyone
else, but I haven't touched a pedal in hours.

The Benz is doing most of the driving, keeping us a comfortable
distance from the cars ahead with its next-gen cruise-control
system. The core of the set-up is a pair of radar emitters -- a
narrow-banded one that pings vehicles up ahead, and a wide-angle
unit that watches the rest of the traffic and keeps a sharp eye out
for road-hogs weaving into our lane. All that locational info is
fed to the car's vehicle-control unit, a computer that smoothly
modulates the brakes and throttle to keep us moving with traffic.
The driver specifies a maximum speed, and the car does its best to
hit that number -- without hitting anything else.

The first time you let the car do its thing is a magically scary
experience. You see the cars ahead closing at a rate that activates
the "I'm going too fast" reflex; your foot hovers over the brake
pedal as your frontal cortex strenuously attempts to override your
survival instinct. Cognitively, you know that this system has been
meticulously tested by obsessive German engineers who would never
let an unsafe car cross the threshold of their shiny factory.

And then, just as you're beginning to contemplate the various
safety regulations that the car must have complied with on its way
to the dealership, you feel yourself slowing -- gently,
autonomously, in perfect control. The cold cannonball in your
stomach turns back into warm muscle, and you chuckle softly to
yourself for being so silly as to doubt such a well-engineered
system. Getting used to these autonomous systems takes time. It turns out that we have to
adapt to the machines more than they have to adapt to us.

Cruise control is just the most obvious sign of a particular
kind of AI that has been accelerating for decades. Think about it.
Anti-lock brakes know when to back off the pedal. Airbags know that
you just smacked into something. Stability control knows that you
just overcooked your Volvo into that hairpin and need a little help
to stay out of the ditch. Your satnav system knows where you are,
your wipers know it's raining, that annoying seat-belt chime knows
you're flouting the law. In short, modern cars are loaded with
sensors and computing power. The 2011 Chevy Volt, for example, runs on some ten million lines of code
-- more than Lockheed Martin's new F-35 Joint Strike Fighter.

The marquee innovation that made intelligent cruise control
possible is the drive-by-wire throttle: the introduction of motor
skills to the automotive body. The throttle is a flap that lets air
and fuel enter the engine. In the conventional setup, it's linked
to the accelerator by a thin metal cable threaded through a grooved
wheel. This went unchanged for decades -- but many newer cars have
done away with the cable. Instead, there is a sensor on
the accelerator and a small electric motor on the throttle.
Step on the accelerator and an electrical impulse travels to the
computer, telling it how far the pedal is depressed; the computer
then tells that little electric motor how wide to open the flap.
Electronics and software are mediating the whole process. Voilà:
you're driving by wire.

Of course, by-wire technology isn't just for throttles. The same
exquisitely sensitive actuation systems are finding their way into
brakes and steering as well. And where there are electronically
controlled systems, there are sensors and software and processors
that can command them. In other words, by-wire technology is paving
the way to truly smart cars.

Drive-by-wire didn't start in the automotive industry. It's a
descendant of an aerospace technology called, yes, fly-by-wire. The
first aircraft to fly with it -- a Canadian fighter jet called the
Avro Canada CF-105 Arrow -- took off in 1958. Most of the pilot's
controls, from the elevators to the rudders, were triggered
electronically.

The advantages -- instantaneous response and lighter weight --
were compelling. Within a few decades, many commercial airliners
were using fly-by-wire technology. It made every aircraft from the
Concorde to the Boeing 777 possible and was integral to improving
autopilot systems -- including those that can land a plane. It's
nice to have Captain Sullenberger (AKA The Hero of the Hudson) on
board, but he's only needed on special occasions.

The by-wire throttle first made its way into cars in 1988, in
the BMW 750iL, and it now makes radar-assisted cruise control
possible in any number of Fords, Volvos, Jaguars and Mercedes. Some
hybrids rely on it to switch nimbly between petrol-driven and
electric power. But drive-by-wire technology has applications
beyond the car-pool lane that conjure scenes from a sci-fi future:
self-driving vehicles that promise the end of traffic jams and a
major reduction in battlefield casualties.